1. Field of the Invention
Included are multiple component spandex yarns that include a release agent. Multiple filaments of the yarns are wound onto the same package to provide a multiple end package with separable spandex filaments.
2. Description of the Related Art
Spandex elastomeric yarns can offer high stretch, good recovery from extension and good fit to the articles made from them, such as weft knit, warp knit, woven fabrics and other textiles. However, the spandex substrate suffers from high tack and friction which can limit commercial applications. Excessive tack is often expressed as fused filament segments and high yarn-to-yarn friction. Also, on being unwound from a yarn package, spandex filaments can experience excessive tension and large, rapid transient increases in tension, which in turn lead to broken filaments during operations such as covering, knitting, weaving and the like. Such tension variations produce non-uniformities in fabrics made with spandex fiber supplied from such packages.
Existing production methods for spandex yarns are based on coalesced multifilament yarns where individual filaments forming the overall yarns are bound together during spinning by pneumatic or mechanical twisting mechanisms in the dry-spinning process.
A process for producing coalesced spandex yarns is described for example in U.S. Pat. No. 3,094,374 which outlines advantages of a multifilament yarn with high inter-filament adhesion with regard to consistent processing and discloses methods for achieving such yarns. However, many textile goods and processes benefit from monofilament spandex yarns where fabric sheerness or low elastic power is desirable. Commercial costs for production of monofilament spandex yarns can be significantly higher due to low asset utilization when compared to multi-filament elastic yarns. JP 03-059112 describes bundled polyurethane multifilaments or monofilaments which are wound up on a bobbin in an oriented manner so that the bundled multi- or monofilaments require 15 mg or less for separation from the bobbin. They are further processed as separate multifilaments or monofilaments at a speed of at least 150 m/min. These products are obtained by subjecting the dry-spun filaments to cooling below 60° C. and by coating the product with a metal soap. U.S. Pat. No. 5,723,080 describes a process for the production of splittable (separable) spandex yarns from a dry spinning process wherein the coalescence of individual filaments is prevented, through the use of widely-spaced spinning jets, laminarized gas flow, and individualized thread guides.
Co-pending PCT Patent Application Publication WO2010/045155, which is incorporated by reference in its entirety, describes spandex fibers prepared by a solution-spinning process where the cross-section includes at least two separate regions with definable boundaries where at least one region defined by the boundaries of the cross-section includes a spandex composition. Examples of cross-sections disclosed include side-by-side and sheath-core.